Collapsible mandrels



June 21, 1960 s. RUSSELL ETL 2,941,744

COLLAPSIBLE MANDRELS 8 Sheets-Sheet 1 Filed Jan. 25, 1956 Raaf/P7- saaao/v Pr/66544, OEA/Ams 650965 200M/waa,

INVENTOR5 BY/ %M/ ATTORNEYS June 21, 1960 R. G. RUSSELL mL 2,941,744l

CQLLAPSIBLE: MANDRELSH Filed Jan. 25, 1956 8 Sheets-Sheet 2 INVENTOFQ5 ATTORNEY`5 June 2l, 1960 R. G. RUSSELL E-rAL 2,941,744

l coLLAPsIBLE MANDRELs Filed Jan. 25, 1956 8 Sheets-Sheet 3 Q3 8O 79 76 79 YI 23 213:1 8

MP7 GO/PMA/ Wma) @EVN/J5 @65 MOMI-75m) INVENTORE BY A ToRNEYs June Z1, 1960 R. s. RUSSELL ETAL 2,941,744

COLLAPSIBLE MANDRELS 8 Sheets-Sheet 4 Filed Jan. 25, 1956 M 12 es E 13% 12a 12h17 22 16 e7 2o sA 3o 4o INVENTOR 5 FIG. 3b.

BY Wl ATTORNEYS June 2l,

Filed Jan.

1960 R. G. RUSSELL ETAL COLLAPSIBLE MANDRELS 25, 1956 8 Sheets-Sheet 5 INVENTORS BY, @d

ATTOR NEY-5 June 21, 1960 R. G. RUSSELL ET AL 2,941,744

coLLAPsIBLE MANDRELS Filed Jan. 25, 1956 s sheets-sheep e FIG. 6.

INVENTOR5 BY @n/r ATToRN EY June 2l, 1960 R, G, RUSSELL ET AL 2,941,744

COLLAPSIBLE MANDRELS 8 Sheets-Sheet '7.

Filed Jan. 25, 1956 xNvENToRs g L f ATTORNEYS June 21, 1960 R. G. RUSSELL ET AL v 2,941,744

COLLAPSIBLE MANDRELS Filed Jan. 25, 1956 l 8 Sheets-Sheet 8 BY ATTORNEYS y a 2,941,744 A PatentedvJune 21, 1960 COLLAISIBLE MANDRELS Robert Gordon Russell, Sheileld, and Dennis George Bloomfield, Rotherham, England, assignors to Davy and United Engineering Company Limited, Sheiiield, England This invention relates to collapsible mandrels or drums for use in coiling strip material, particularly strip metal received from rolling mills; and an object of the invention is to provide a robust yand eiiicient mandrel that is very suitable for use with hot strip steel received from a hot mill.

According to the present invention, a collapsible mandrel or drum includes a rotatable shaft, a number of segments distributed round the shaft and presenting a mandrel surface, on which strip material can be coiled, means for transmitting torque from the shaft to the segments, means for adjusting the radial distance from the shaft axis of the segments, which are locked in an extreme position corresponding to the expanded condition of the mandrel, and resilient means mounted to act be tween the segments and an abutment which is xed against translational movement, at least when said means for adjusting the segments are locked, so as to enable the segments to yield in the event of an abnormally large hoop stress in material coiled on the mandrel or drum being encountered. 'I'he said means for adjusting the radial distance of the segments, i.e. for causing the expansion and contraction of the mandrel, may comprise wedge faces on the shaft mating with wedge faces on the segments, so that, as the latter undergo their axial movement, they ride inwards or outwards on the wedge faces of the shaft.

The mandrel shaft is preferably tubular and the axial movement imparted to the segments by an actuating or control rod extending through the shaft and coupled to the segments beyond one end of the shaft. In this case the mandrel is, of course, supported by bearings carrying the shaft beyond the opposite ends of the segments.

Advantageously the torque is transmitted between the shaft and segments by interengaging parts formed respectively on the shaft and segments, these parts being provided with lips and recesses inclined similarly to the wedge faces, to move over one another and ensure that the mandrel contracts when the segments are moved longitudinally in the appropriate direction.

The aforesaid actuating rod may be moved towards and away from the position in which the mandrel is expanded by means of a toggle linkage that is locked in the dead centre position when the mandrel is expanded. Then the resilient means may be interposed between one end of the toggle linkage and an abutment, so that the centre linkage in its dead-centre condition, can yield longitudinally against the action of the resilient means in the event of abnormal radial pressure on the mandrel arising. Preferably, however, the resilient means are interposed between the actuating rod and the segments.

A very important feature of the invention, believed to be new in itself, consists in a collapsible mandrel or drum including a rotatable shaft, anumber of segments distributed round the shaft and presenting a mandrel surface, means for transmitting torque from the shaft to the segments, means for adjusting the radial distance from the shaft axis of the segments, sealing means interposed between adjacent edges of the segments to provide in all conditions in the range of expansion or contraction of the mandrel a sealed conduit within and extending along the mandrel, and means for causing liquid to ow into the conduit to cool the mandrel and lubricate the means for adjusting the segments radially.

In order that the invention may be clearly understood and readily carried into effect, apparatus in accordance therewith will now be described, by way of example, with reference to the accompanying drawings in which:

Figures la, 1b constitute a side elevation, shown partly in section, of a mandrel or coiler drum assembly,

Figures 2a, 2b constitute a vertical section through part of the assembly shown in Figures la, 1b,

Figures 3a, 3b constitute a vertical section similar to that of Figures 2a, 2b but showing the parts in a different operative condition.

Figure 4 is a section on the line l'V-IV in Figure 2b,

Figure 5 is a section on the line V-V in Figure 3,

Figure 6 i s a section on the line VI-VI in Figure 2a,

Figure 7 is a section on the line VII-VII in Figure 3,

Figure 8 is a diagram showing a modification of the assembly of Figures l to 7,

Figure 9 is a side elevation of a detail;

Figure l0 is a section on the line X-X in Figure 9 Figure l1 is an end elevation of the detail of Figure 9' as viewed in the direction of the arrow Xl;

Figure 12 is an end elevation of a further detail.

Referring particularly to Figures la, lb, 2a, 2b, 3a, 3b, the assembly comprises a central shaft. having portions 1, la at its right hand end lying within the mandrel or drum M proper. To the left of the mandrel M the shaft comprises a series of portions 1b v1]' of varying diameters. The left-hand end 1j of the shaft is connected to be driven by a collar 2, shown in chain lines in Figure la, by an electric motor with intervening reduction gear (not shown). The shaft is supported by an anti-friction thrust bearing 3 (described in greater detail below) em bracing the portion 1c and by an anti-friction bearing 4 (also described in greater detail below) embracing the portion 1f.

The shaft 1 1j is tubular and an actuating rod 5 for the mandrel extends therethrough, being supported in -bushes 6, '7 in opposite ends of the shaft with sealing ring 6a held by collar 6b but having some clearance with `respect to the shaft along the major portion of its length.

The actuating rod or member rotates with the shaft and is arranged -to reciprocate relatively thereto. Within the mandrel proper the portion 1 of the shaft is of square cross-section (Figures 4 and 5) and about this square portion of the shaft are arranged four mandrel segments S registering respectively with the four faces of the portion 1 of the shaft. The arcuate faces 9' of these segments 8 are such that, when the mandrel is expanded to its full extent, they llie on a true cylinder. Intermediate the ends of the square part yof the shaft, each face thereof is formed with a series of three wedge faces 10 (Figure 2b), each making an angle lof l5 degrees of arc with the horizontal. Each such wedge face 10 is formed with a recess in which is located a replaceable block 11 of bearing metal having its exposed face parallel to that of the wedgeface. Mating with each set of three such bearing blocks ll1 is a wedge member 12 fixed by screws 12a in a recess 12b in the inner face of the mandrel segment 8 that registers with the face of the square portion 1 of the shaft on which the blocks are mounted. Each such wedge member 12 is', therefore, formed `on its inner face with a series of three wedge faces 13, each lying at an angle of l5 degrees of arc to the horizontal.

Beyond the wedge faces at the forward end of the mandrel, that'` is to say vthe free end of the mandrel remote from the bearings 3, the square portion 1 of the shaft is ktowards the forward end of the mandrel.

extensions 23. centrifugal force of the segments 8, when not bound by formed respectively oniits'four dat faces with four radial yEach such recess 155 is inclined at-'the same angle as the aforesaid wedge faces and in theY same sense, that is to say inwardly towards the mandrel wis as they extend The outer faces 16 of the projections i4 are similarly inclined. Eachsegrneut 8 is formed with a cavity 17 into which the associated projection 14 extends. The cavity 17 is provided with lateral lips 18 that extend into and are inclined similarly to the recesses 1S. Bearing lmetal '19 `is mounted on the lips 1S to'engage the inner 'faces of the wings 14a. Bearing metal 20 is also mounted on the sides of each cavity 17 to bear on the sides of the associated projection i4, outwardly of the wings 14a. The outer face 2.2 of each cavity is inclined similarly to the outer face 16 of the associated projection 1-4, but there is a little clearance between these two faces. The cavity 17 isl longer than the projection 14 in the direction of the mandrel axis so Vas to enable the segment to move longitudinally with respect to the shaft, while the lips 18 travelv up or down the undercut recesses 15. At the rear end of the mandrel M proper, that is to say at the opposite ends of the wedge memberv 1-2, four further sliding connections are provided between the shaft 1 and the segments S. Thus, each segment 8 is formed at its lefthandf end, as viewed in Figure 2a and 3a, with an extension 23 formed' along its inner edges with wings 23a having bearing metal liners 24 applied to their radially outermost faces. ach extensionV 23 'slides in a slot Z5 inthe portion 1a (Figures 2a, 3a and 6) of the shaft,

this portion being a circular portion of less diameter than the expanded mandrel butV of greater diameter than that of the contracted mandrel segments. Each slot 25 is formed with undercut lateral recesses V26 in which the lwings 23a of thek associated extension 23 slide. Bearing liners 27' are interposed betweenA theA sides of each slot 25 The necessary torque is transmitted from the shaft to `the segments 8, when the shaft rotates,by the sides of the projections 14, acting'onthe sides of the cavities 17, and

by the sides of the slots 25, acting on the sides ofthe Outward movements under gravity or a coil, is prevented` by the outer surfaces of the undercut Yrecesses 2o acting on the wings 23a and by the lips 18 acting on the wings 14a.

At its extreme forward end, beyond the portion 1 of the mandrel shaft, ythe controlfrod carries a cruciform pla-te 23 (Figures 2b and l2), at right angles to the mandrel axis, faced on both faces with bearing blocks 2.9. Figure l2 shows the plate 28'with the blocks 29 removed therefrom. These blocks 29 are mounted to slide in slots 30 formed on the inner faces of the segments 8 near the forward ends thereof. The means (described below) of attaching the plate 28 to the rod S are such that axial movement of the control rod is communicated to the segments 8. Thus, as the right-hand end of the rod 5 is pulled towards the left-hand end of the shaft 1 1y', the wedge members 8 rise up the wedge blocks 11 causing the mandrel to expand; from the condition indicated by chain lines X in Figure 2b to' the full line position of Figureb the expansion being limited by the nature of the rod actuating mechanism asfdescribed'below,

When the movement offthero is reversed, contraction of the kmandrel is ensured bythe wings 23a riding down theffundercut recessesl 'Gand by the lips 18 riding down thel'recess 1:5; The contraction` of the mandrel is end plates=47a (Figure'S) or47 (Figure la).

now exclusively to Figure 1a, it will be observedV that'the l limited by the nature of the rod actuating mechanism described below.

The rod 5 is a sliding it in a anged bush 31 at the centre of the cruciform plate or connecting member 28 but normally the plate 28 behaves as if it was an integral part of the rod 5, being heldin contact with a flange or abutment 32, formed on the rod 5, under the action of a compression spring 33 which reacts Vagainst a plate or abutment 34, formed with a central aperture withinl which the rod 5 tits, the plate or abutment 34 being held on the rod 5 by a circlip'35 sprung into a groove in the rod 5. The spring 33 is enclosed by telescoping tubes 36, 37 respectively forming parts of the plates 28, 34. The flanged bush 31 provides the abutment for the left-hand end of the spring 33. A sealing member 39 is mounted to slide on the outer tube 37 and is formed with an annular face 4t? that bears on vertical faces at the ends of the segments 8. The face 40 is maintained in contact with lthe* segments by three compression springs 41, only one ofA which appears in Figure 2b, equidistantly spacedabout the axisof the mandrel. The sealing. member 39 is formed with a collar 39a that surrounds the tube 37 with a little clearance. Three arms 34a project radially outwards from the plate 34, through slots in the uppecedge of the collar 39a, over portions 39h of the sealing member 39. These portions 3911 are formed with cavities, between the inner` ends of which and the arms 34a the springs 41 act.A

If the hoop stress applied to the mandrel M becomes excessive, the segments 8 can yield radially inwards against the action of the compression spring 33, so as to eliminate undue stress in the mandrel and, incidentally, in the material being coiled. When this occurs the wedge faces '13 slide down the bearing blocks -11 and the lefthandV faces of the sl'ots 30 in the segments 8 force the plate 28 to the right and so compress the spring 33 against theplate 34. In this action the plate 28 separates from the-ange 32 on the rod 5, it being understood4 that, when the mandrel M is in the expanded condition, the rod'S isl locked against movement to the right by means now to be described. For this prupose itis necessary' to turn tothe-rear lend of the mandrel shaft 1 17', behind the anti-friction bearing 4 (Figure la). However, the means whereby the rotating rod 5 is acted on so as! to cause the mandrel to expand and contract comprise a non-rotatable cylinder 42 mounted for reciprocation along theaxisof the shaft andthe parts within this cylinder are the same as the parts ywithin a cylinder 42a in Figure 8, which showsw a modification of mechanism appearing in Figure la. Thus, the rod 5 carries a transverse cotter 43 which projects through lateral slots 44 formed longitudinally in the part 1iy of the mandrel shaft, theslots 44 vbeing long'enough to enable the rod 5` to undergo the full extentof its required reciprocatory movement. Beyond these slots the opposite ends of the cotter 43, iitinto apertures in a sleeve 45, free to slide longitudinally on the part 11' of the mandrel shaft, but constrained by the cotter 43 to rotate therewith. The sleeve rotates'in-anti-friction bearings 46 in the* cylinder 42a, the bearings 46 being held in position laterally by Referring cylinder 42 is furnished with diametrically opposed coaxial trunnions `48 (only one of which, however, appears in Figure Y la) Each trunnionr'is'rotatablyy mounted in a bearing-block 49' slidably'mounted between the prongsof `av fork 50. The block 49 bears on one side directly againstv one prong of the fork andagainst a replaceable bearing memberv 51- ou the other'side. The forks' 50 yare formedrespectively atthe'upper ends of armsV S2 fixed together bycross-pieces 53, S4- and pivoted about the horizontal axis of ajournal 55. Between the arms 52'" is pivoted,-about the axis ofa journal 56, a double link comprisinggtwo parallelV parts xed together by a crosspiece 58; The twoparallelvparts of-'the doublelink57,

forming one part of a toggle linkage, lie on opposite sides of a fork 59, at the top of a piston rod 60 in a double acting piston and cylinder assembly 61, mounted to rock about the axis of a journal 38. Between the two parts of the fork 59 a web 62, forming part of a link 63, is

located, the fork 59, web 62 and link 57 being pivotally connected by a gudgeon 64. The link 63 constitutes the second part of the toggle linkage. The right hand end of the link 63 is furnished with parallel ears 63b lying on either side of a xed lug 65 to which they are pivoted by means of a journal 66. The link 63 is formed with an abutment 67, that bears against an abutment 68 on the cross-piece 58, when the mandrel M is expanded to the maximum extent. The axes of the journal 56, the gudgeon 64 and the journal 66 are then in one horizontal flat plane and pressure is preferably maintained above the piston in the piston and cylinder assembly 61, the engagement of the abutments 67, 68 limiting the downward movement of the piston. The alignment of the three said axes means that the rod 5 cannot be moved to the right under the action of excessive hoop stress .applied to the mandrel M and necessitates the provision Vfixed but can yield against the action of a compression spring 33a contained in a telescopic cylinder 69 (the outer portion 70 of which is xed in space). In this arrangement excessive hoop stress on the mandrel M does cause the rod 5 to move to the right, swinging the Iarms 52a clockwise and V`compressing the spring 33a .through the medium of the linkage 57a, 63a. The cylinder in the piston and cylinder assembly 61a is pivoted about a fixed axis 38a so that the movement may be accompanied by a slight movement of the piston in the cylinder. In this modification the plate 28 is fixed to `the rod 5.

When it is desired to cause the mandrel M to contract to the condition indicated by the chain lines X in Figure 2b, liquid pressure is admitted beneath the piston in the piston and cylinder assembly 61 or 61a, while liquid is exhausted from the space above the piston causing the linkage 57, 63 to fold while swinging the arms 52 or 52a clockwise and moving the rod 5 to the right.

In order to enable the mandrel M to be dismantled, lthe rod 5 is moved further to the right than is the case inthe ordinary operation of the device. For this purpose vthe replaceable bearing members 51 (Figure la) are removed from the position shown and located between the I opposite faces of the blocks 49 and the left-hand prongs ofthe fork 50. Therefore the entire assembly comp1ising the rods and the segments 8 `is moved to the right,

relatively to the `forks 50, to the position shown in Figures 3a, 3b in which the lips 18 are clear of the wings 14a and the wings 23a are clear of the slots 25, whereby the segments 8 are freed from the shaft 1 1]' and can be removedradially.

. The strip is wound on the mandrel M in the vicinity `of the bearing blocks 11 so as to avoid' bending of the segments 8 at their forward ends. Therefore, the longi` tudinal edges ofthe Isegments 8, in the vicinity of the bearing blocks 11, are formed with series of projections 72, the projections 72 on the edges of each segment 8 being `interdigitated with the projections 72 .on the adjacent arcuate surfaces' of the segments and give adequate support to the wound strip between the main bodies ofthe segments 8. j Y l The mandrel M is designed for coiling strip delivered from a hot rolling mill and is, therefore, water cooled. For this purposet-he cylindrical portion 1b of the shaft, just to the rear of the segments, is formed with an annular recess 73 surrounded by a sleeve 74, formed with ports 75. The sleeve 74, in turn, is surrounded by a stationary sleeve 76 formed with an internal groove 77 in register with the ports 75. Water is pumped into the groove 77 through a pipe 78 (Figure lb) and lateral leakage from the sleeve 76 is prevented by two sealing rings 79 held in position by collars 80 lixed to the sleeve 76.

The water leaves the annular recess 73 through four passages 81 formed in the part 1a of the mandrel shaft. The passages 81, at their forward ends, register respectively with the ends of short grooves 82 formed in members 83 xed respectively in corners in the square part 1 of the mandrel shaft by screws 84, the members 83 being formed with V-shaped bearing portions 85 that tit into the corners of the square part 1 of the mandrel shaft between the bearing blocks 11 as shown in Figures 4 and 5.

The water escapes from a space 82a (Figure 9) at the rear of the bearing portions 85 into spaces 82th (Figures 4 and 5) between anges 86, formed on the members 83, and the sides of the wedge members 12.. The outer edges ofthese anges 86 are a neat sliding lit in slots 87 in the segments 8. It will be seen that the spaces 82h between parallel flanges 86 that is to say, the flanges on opposite sides of any one wedge member 12 are joined by the gaps 82e (Figure 2b) between opposite wedge faces l1() and 13. The bearing portions 85 do not extend as far as the end of the mandrel shaft and the water streams in each pair of spaces 82a unite beneath the associated flanges 86 beyond the associated bearing portion 85, so that the mandrel shaft is then entirely surrounded by water. Beyond the mandrel shaft the water enters the space 82C surrounding the rod 5 and is discharged from this space (Figure 2b) through four passages 28a in the cruciform plate 28. Beyond the plate 28 the water escapes from the mandrel. However, the sealing member 39 ensures that part of the water is deflected towards the centre of the mandrel and escapes between the tube 37 and collar 39a. Water is prevented from escaping back-wards along the rod 5 by sealing ring 6a held in position by collar 6b.

Returning to the thrust bearing 3 it will be seen that this` comprises two rings of taper rollers 88 (Figure 2a), on inner races 89 surrounding the part 1c of the mandrel shaft and clamped in position between collars `90 by nuts `91 screwed onto the part 1d of the mandrel shaft, the

reaction being taken by the end' of the part 1b of the mandrel. The rollers run on an outer race 92, clamped against a face 93 on a stationary sleeve 94 by a collar 95. The thrust bearing 4 likewise comprises two rings of taper rollers 96, running on inner races 97 clamped betweencollars 98 by nuts 99 screwed onto the part 1h of the mandrel shaft, the reaction being taken by the end of the part 1e of the mandrel shaft. The stationary race 100 is mounted similarly to the race 92 of the bearing 3, in a sleeve 101.

It is to be understood that the metal bearing blocks and bushes referred to above may be replaced by nonmetallic units; for example, a synthetic resin with a fabric filler. It is also to be understood that the water used for cooling also serves to lubricate the various sliding surfaces. The cooling effect of the water makes possible the use of non-metallic bearings that are bad conductors of heat.

What we claim is:

l. A collapsible mandrel assembly comprising, in combination, vfixed supporting means, a shaft mounted for rotation on said supporting means, a number of segments distributed around saidshaft and presenting a mandrel -perrnitting radial adjustmentfof .said segments, means,

fincludingmember's formed with wedge -faces engaging like f'wedge faces on the segments, for adjusting sa-id seg- ,.rnents radially, means for looking vsaid segments :in -an fextreme position -of .radial `adjustment corresponding to :the expanded 'condition of the mandrel, San 'abutment xed against translational movement relatively 'to said supporting means, atleast solong assaid means'for adjust ring :said segmentsk are locked as aforesaid, Yresilient means :mounted to act between said segments `and :said .-.abut- :ment so as to enable saidrsegrments Vto*yieldvinttheevent of abnormally large hoop stress in material coiled :on the mandrel being encountered, and means, Vincluding "said members formed with -wedge faces, -dening zducts AVextending axially along thermandreltclose to them-andrel surface for conveying copiousy quantities lof water for -coolingthe mandrel inthe expanded condition.

2. A collapsible mandrel..according5to;claim;.l,.inwhich .saidmeans for adjusting saidssegmentsvradially includes .means 'for .moving said segments .to--andfro in .thelaxial *direction with :respect to` said shaft and mechanisminterfposed r'betweensaid shaft Vandfsaid segmentsifor autolm'atically adjusting the radial distancefof saidse'gments from 'the .shaft axis .a function of the "axial position oflsaid segments relatively `to`said shaft.

3. A collapsible Vmandrel-comprising inicombination, 'a tubular shaft mounted for rotation *and provided with 'wedge faces distributed therealong and `thereabout, a

plurality of segments, each'formed with frows ofwedge 'faces mating vwith rows of wedge lfaces on fsaid shaft,

-said segments presenting a 'mandrel sur-faceon -which 'strip material canbe coiled, a member mounted'to reciprocate in said tubular shaft, means connectingsaid segments to said member to transmit Vaxial movement to/said segments while-permitting them to moveradially inwards and outwards as they rideonesaid -"tirst-men ltioned -wedge faces, means for retaining saidfsegments onsaid shaft while permitting said axial 'and radial'move- 'ment of said segments, means for transmitting torque `from said shaft to ysaid segments, and Vmeansincluding said segments defining ducts extending axially along the mandreL close to the mandrel surface, for `conveying :copious quantitiesr of tuid'for cooling the mandrel, said ducts being open when vthe mandrelis in Yexpanded condition.

4. A collapsible mandrel according to claim v3, `in

Nvhich said means for .transmitting torque'betweensaid shaft 'and said segments comprises interengagingparts `fortified respectively on said shaft and 'said segments, `said parts being provided with interengaging'wings and recesses, inclined similarly to said wedge faces and overlapping -so that their interengaging'surfacesforce said segments radially inward toward said "shaft when Vsaid segments are moved longitudinally in .the appropriate direction.

`5. A collapsible mandrel comprising, in combination,

'supporting means, a shaftmountedfor 'rotationon said lsupporting means, a plurality Aof segments distributed round said shaft and presenting a mandrel surface on vwhich strip material can be coiled, .meansfor transmitting torque between said shaft and said segments, Ymeans for. 'retaining said segments on said shaft While;permtting A axial movement of said segments .and radial Yadjustment thereof, means for moving said segments to-and-fro in fthe axial direction with respectto said. shaft, mechanism interposed between said shaft and said segments for automatically adjusting the radial distance ofsid segmentsrfrom said shaft taxis asa function .of the axial lposition "of said .segments relatively to said-sshaft, said means for moving said segments to-and-fro includinga 'to-hold said .segments in their radially .outermost .p0- sitions, means for holding said toggle linkage in sits idead centre position, an abutment'xed against translational movement relatively to said supporting means, .at least -so long as said toggle linkage is vin its'dead-centre position, .resilient means V`mounted to act between `said segments and said :abutment so as :to enable Vsaid segments `Vto yield `in ythe event of abnormally `large hoop stress vin material coiled on ythe mandrel being encountered, and 'means including -said segments ,defining ducts extending axially along the mandrel, close'tothe mandrel surface, for conveying .copious quantities of fluid :for cooling the mandrel, said ducts being open -whenythe mandrel is inexpanded condition.

6. A `collapsible mandrel according Yto claim -5., rin which said shaft is hollow and in Ywhich :said `means for moving said segments to-and-fro include an'actuating member reciprocable within Y said shaft Iand operatively .connected with said toggle-linkage, said resilient means being interposed 4between said member zand said segzments.

`7. A collapsible mandrel comprising, .in combination, a hollow shaft mounted `for rotation, a plurality of :seg-

Vmen-ts distributed round said .shaft and presenting a lmandrel surfaceon which strip material can Vbe coiled, means for transmitting torque between lsaid shaft :andi -s-aid segments, vmeans for retaining said segments onsaid .shaft while permitting axial movement 0T said segments and :radial l.adjustment thereof, an actuating member .mounted to reciprocate in said shaft and having an end `projecting outside said shaft, said projecting Yend being provided with two axially spaced abutments, a rconnecting member `surrounding said Ashaft between lsaid vabutments, a helicalcompressionspring surroundingsaid projecting end land holding said connecting member -against the inner one of said abutments while reacting against the outer one ofsaid .abutments, said segments being engaged by `said connecting member so as `toHmove yaxially -toaand-fro with said reciprocable member but 'freeto move radially towards and awayfromsaid'shalft, vmecl'ianism interposed between said shaft andlsaid seg- `ments A'for automatically' ladjustingl the radial distance of said segments from the shaft axis asa function ofl'the axial yposition of said segments relatively to 'said shaft, a fixed abutment member, a toggle-linkage 4interposed Abetween said abutment member and .said reciprocable member, and means for causing said toggle-linkage t0 foldand open :to ya deadfcentretcondition 'tocause the segments to move radially inwards and outwards.

A8. A collapsible mandrel comprising in combination, a tubular shaft mounted 'for rotation andrprovided with wedge faces distributed therealong and thereabout, a `plurality of segments, each formed with rows Vof wedge faces mating with rowsof wedge'faces on .said,shaft, 4said "segments presenting 'a mandrel. surface on which sii'iP material can be coiled, a member mounted to.recip10.Cate in said .-tubular shaft, means connecting saidsegmentsto said member to 4transmit axial 4movement to said segments while permitting them to move radially linwards andantwards asthey ride on vsaid rst-mentioned wedgejfaces, meansfor. retaining .said segments onssaid shaft while permitting said axial and radial movement-.of .saidsegments, means .for transmitting torquegfromesaidshaft to said segments, means, including said segments, de-

'ining ducts extending along thelinteriorf said. mandrel,

said ducts being open when said segmentsare in,t;heir

' outermost positions, and means'for delivering 'liuidthrough saidducts for coolingsaid segments when .insuchouterrmost` positions and. lubricatingsaid mating wedgeH faces.

9. A- collapsible mandrel comprising incombination, `a tubular shaft ymountedlforrota'tion andprovidedfwith wedge facesfdistributed therealong and therea-bont,.,a:plurality of` segments, distributed around saidshaft andeach IQgSlCsliUkge arranged IQ llkllp 'a .d eat Centro-position .formed alongthe outerface with anarcnatesurfaceand along the inner face with a row of wedge faces mating with a row of wedge faces on said shaft, said segments presenting a mandrel surface on which strip material can be coiled, a member mounted to Ireciprocate in said tubular shaft, means connecting said segments to said member to transmit axial movement to said segments while permitting them to move radially inwards and outwards as they ride on said first-mentioned wedge faces, means for retaining said segments on said shaft while permitting said axial and radial movement of said segments, means for transmitting torque between said shaft and said segments, spaces for liquid extending along the mandrel between mating pairs of rows of said wedge faces, a stationary manifold surrounding the mandrel at one end thereof and formed with passages for liquid, the mandrel being formed with passages adapted to receive liquid from said manifold during the rotation of the mandrel and deliver the liquid to said spaces, sealing means interposed between adjacent edges of said segments to provide, in all conditions in the range of expansion and contraction of the mandrel, a sealed conduit within and extending along the mandrel to enclose said spaces, and means defining passages for the escape of liquid from said conduit.

10. A collapsible mandrel comprising, in combination, a shaft mounted for rotation, a plurality of segments distributed round said shaft and presenting a 'mandrel surface on which strip material can be coiled, means for transmitting torque from said shaft to said segments, means for retaining said segments on said shaft while permitting radial adjustment of said segments, means for adjusting the radial distance from the shaft axis of said segments, sealing means interposed between adjacent edges of said segments to provide, in all conditions in the range of expansion and contraction of the mandrel so as to provide -a sealed conduit within and extending along the mandrel, and means defining Ipassages for the entry of liquid into and the discharge of liquid from said conduit, said segments being formed with slots extending longitudinally thereof slightly inwards of the arcuate surfaces on said segments, and said sealing means comprising longitudinal flanges extending into said slots.

11. A collapsible mandrel comprising, in combination, a shaft mounted for rotation, a plurality of segments distributed round said shaft `and presenting a mandrel surface on which strip material can be coiled, means for transmitting torque `from said shaft to said segments, means for retaining said segments on said shaft while permitting radial adjustment of said segments, means for adjusting the radial distance from the shaft axis of said segments,

sealing means interposed between adjacent edges of said segments to provide, in all conditions in the range of expansion and contraction of the mandrel so as to provide a sealed conduit within and extending along the mandrel, and means defining passages for the entry of liquid into and the discharge of liquid from said conduit, each of said segments being formed along its outer :face with an arcuate surface, said sealing means comprising members fixed to Iand expanding along said mandrel shaft respectively between the segments in each pair of adjacent segments, each said segment being for-med close to its longitudinal edges with slots disposed slightly inwards of the arcuate surface of said segment and each said member being formed with two flanges projecting into slots in the two adjacent segments.

12. A collapsible mandrel comprising, in combination, a shaft mounted -for rotation, a plurality of segments distributed round said shaft and presenting a mandrel surface on which strip material can be coiled, means for transmitting torque from said shaft to said segments, means for retaining said segments on said shaft while permitting radial adjustment of said segments, means for adjusting the radial distance fromthe shaft axis of said segments, sealing means interposed between adjacent edges of said segments to provide, in lall conditions in the range of expansion and contraction of the mandrel sogas to provide a sealed conduit within and extending along the mandrel, and means defining passages for the entry of liquid into and the discharge of liquid from said conduit, each of said segments being formed along its outer face with an arcuate surface, said shaft having a length of square cross-section and there being four segments arranged respectively face-to-face with the faces of said length of square cross-section, said segments being formed with parallel slots on their inner faces, close to their edges, and said sealing means comprising four members xed respectively to the corners of said shaft length and each formed with two iianges at right angles having a near sliding fit respectively in slots in adjacent edges of two segments.

References Cited in the tile of this patent UNITED STATES PATENTS 824,292 Gerhard June 26, 1906 2,202,563 Mikaelson May 28, 1940 2,352,580 Wettengel June 27, 1944 2,578,953 Tyrrell Dec. 18, 1951 2,586,527 Ferm ---a Feb. 19, 1952 2,591,730 Sendzmir Apr. 8, 1952 2,762,576 Herr Sept. 11. 1956 

